1. Field of the Invention
The present invention relates to a wireless communication network; more specifically, a wireless network with a reconfigurable infrastructure.
2. Description of the Related Art
Traffic densities serviced by wireless systems are often not constant during the day: e.g., in a city environment users living in the residential areas need a certain amount of interactive services in the morning (reading their e-mail, select breakfast news highlights, etc.), use more interactively during working hours at their business location (industrial region, or commercial sites in the city center), and want interactivity for their leisure time at home in the evening (internet games, etc.). So both the location and the nature of the interactive services needed changes during the day. Current wireless networks are not laid out to respond to these changes in traffic density. At certain moments, "hot spots" may occur in the network, i.e. traffic demands which locally exceed the fixed wireless capacity available, leading to rejection of calls and thus of revenues.
Current wireless systems are divided into regional areas called cells. Each cell uses one or more dedicated microwave carrier frequencies, with each frequency carrying a limited number of (voice or data) connections. The microwave carrier frequencies available in a wireless network are usually assigned among the cells in such a way that adjacent cells use different frequencies, in order to avoid interference problems. A common network structure consists of hexagonal cells 10 with the transmit/receive antenna in the middle, arranged in a cluster 12 containing seven cells. FIG. 1 shows the layout of such a cluster. By repeating this structure, a large geographical area can be covered. This fixed configuration is not sufficiently responsive to changing traffic densities.